Reinforcement for pneumatic tires.



- A. L. MURRAY.

RBINE'ORGEMENT FOEPNEUMATIG TIRES.

I APPLIGATION FILED DBO. 2B, 1912. 1, 1 3,424. mama mar. 2, 1915.

mms mus. me., Auna:H msmsamu. n L

ALBERT LINE' MUY, 0F AUBURN, INDIANA.

nnnvroneirrnrir ron rimaniamo riens.v

1&369424.,

Speccatioii of Letters Patent.

Patented Mar. 2,

. applicati@ niet niemeer as, :mial semi no. recaen.

To all 'whom it may concern Be it known that l, ALBERT LINN Mue- RAY, a citizen of the United States, res1ding at Auburn, in the county off' Dekalb and State of Indiana, iave invented new and useful Improvements in Reinforcements for Fnennnaticv Tires,- 'of which the following 1s a speciiication.

My inventiton relates to reinforcements ior pneumatic tires and particularly to 1nner reinforcements for the outer casings of such tires.

The object of my invention is to provlde an inner reinforcement for pneumatic tires which shall'take part of the stra-in off the outer casing of the tire and thereby 1ncrease the life and durability' of the casin l gin the use of a reinforcement in a tire the production of heat by friction bet-Ween the surfaces of the casing and the reinforcement must be guarded against. found the material' beet suited for the structure of thev reinforcement to be the same material as the rubberized fabric body out of which the casing is niadefethat 1s, several plies of cotton fabric impregnated with rubber and joined by vnlcanization. Such material in a reinforcement is capable of withstanding the same amount of flexing which is required of the casing. In order that frictional heat 'and cnaiing between the casing and reinforcement shall be obviated l have found that the reinforcement should be of a very flexible nature in order thattlie air pressure Within the tire may hold the reinforcement so firmly against the wall of the tire that' the flexing operation will taire place principally Within the fabric body of the reinforcement. In accomplishing this result I 'have found that the vreiniorcenflent should be somewhat lighter or thinner than the regular body of fabric used in the tire casing. For example, Where `a tire casing is composed of live plies of 17% oz. fabric, a

reinforcement formed of the same number of plies of the same Weight material will exert more resistance against the flexing or the reinforcement than the 'air under pressure in the. inner tube can overcome; consen quently relative movement between the cas ing and reinforcement takes place. t to lows that such a reinforcement. will heat or chate badly. However, if the reinforcement is formed of ve plies of a ligli'ter weight ci i l have greatly decreased should it become locked in it smaller at any 'point than the ysize necessary to meet the inside Walls of' the casing rand rim. Both the outer casing and the reinforcement, however, will become very durable if the reinforcement is only required to assist or relieve the casing and thereby prey vent either the casing or the reinforcement from receiving the full strain 'of the air pressure in the inner tube alone at any point. Should. the outer casing break at any point,l the reinforcement has sufficient strength to hold the pressure of the inner tube temporarily, thereby preventing,"` a

blowout and the necessity of changing tires along the road.,

lt is obvious that a reinforcement should not interfere with nor-increase the labor or effort required in the plaeing'of a tire on the Wheel rim, as-that operation is usually performed. lt is also desirable that the reinforcement should be adjustable to such variations of tire sizes as occur `in tires ofdierent manufacture, and also that it may accommodate itself vto a new and unstretclied tire and to one `which' is old or fully stretched 'by use.

The' best mannerof accomplishing the above requirements is to form tliereiniorcement with an opening along its `ii'iner periphery sol that the inner tube may be readily inserted. The open edges' of the reinforcement overlap and are so formed th they will interlock or become immovab e against further extension when the tire is fully inflated with air. 1

Heretofore tire reinforcements 'havel been made in which the overlapping edges have been serrated, or are provided with other forms of interlockingelements. But such constructions are dective because the serrations or interlocking parte engage each other when. the casing is pl on the 'such a manner as to make a cross s'ection` of the first llight air Consequently, the engaging parts become relatively immovable on the application of I pressure to the tube with the result that all 'the air pressure strains,

vwhere the tire is fully inflated, are exerted upon the circle formed by the reinforcement, and the reinforcement itself will burst l'or tear apart within a much shorter `time A v.than the ordinary life of thetire. 1Q,

By my invention have overcome the dif- `'z-iculties encountered heretofore in the use of the same,

1 parts when the tire 1s inli'ated. and Fig. 3 is an enlarged section of the reinforcement.

ias

'Referring` to the drawings/10 is the rim of a wheel of any well known form; 11 is Vthe outer casing of the tire of any well Sk'nown .form having its beads 12 in engage ment with the rings 13 on the rim. Within 259? iiijthe reinforcement is the: inner tube '15.

theeasing is the reinforcement 14 and withreinforcement is formed of a plurality plies ofl fabric which are impregnated with/rubber and vulcanized together simiein larlly to the plies of the casing., but the fabric body of the reinforcement is con f of cotton duck less in thickness than that of the casing. It is providedV with an opening which extends entirely around its inner periphery and the reinforcement is of sucient width to insure the' continuous conn tact of the overlapping portions whether the tire is infiated or deiated. The reinforcement adiacent each open edge is bev eled or @ered so that the edge of the fabric body is of considerable thinness. preferably of no greater thickness than one of the plies of rubberized fabric of the reinforcement.

lln Fig. 3 l show 'the reinforcement formed of three plies, although there may be any suitable number of such plies in the entire body of the reinforcement orat ant7 desired point or points thereon. The ply 15. which, in the assembled tire preferably makes contact with the inner tube.y is wider than the others; that is it extends to the onen edges of the reinforcement. The middle ply 16 1s some' hat shorter than ply 15" and ply 1'1" overlaps the edge of ply 16 and is joined to Vply 15 but does not extend to the edge of ply 15. The outer surface of ply 17 there fore produces a beveled effect; near the open edge of the reinforcement. The beveled surface on the reinforcement may be produced in any convenient manner, that shown in -by gripping lapping portions cannot the drawing beinglonly one such manner of producing such a surface. The beveled por .v

tions of the reinforcement materially aid in the sliding of the overlapping portions of the reinforcement as the tire 1s inflated and when-the tire is fully inated said surfaces assist in. securing the reinforcementin place the adjacent insider-surface of the casing and theinner surfac'e'ofl the reinforcement. The .sa-id beveled surfaces by virtue of their grippingelfect will`necessaril.7 tend to retard the expansion of the rein orcement especially when the tire is fully iniated with air, since the thin beveled edge of the outer flap is bound tightly between the casing and reinforcement by the airunder pressure in the inner tube.

In Fig. 1 the tire is deiiat'ed. The overlapping portions of the reinforcement are slid upon each other to such extent that the reinforcement is considerably smaller than the inner wall of the casing, the edgesof the reinforcement being indicated by numerals 18, 18. The casing may, therefore,

be readily placed on the rim. As the inner tube is inflated the overlapping portions slide on each other to extend the reinforcement to meet the inner wall of the casing,

and when the inflation is complete the edges 18 of the reinforcement will assume a position approaching that shown in Fig. 2. in this position the central part 19 of the overlapping' portions between the'beads 12 is curved sharply to meet the rim 10 and to conform to the contour of the beads 12. This sharply curved portion together with the grip of the beveled edges of the reinforcement locksv the reinforcement to the casinga and since the air pressure in the tube is the same in all directions, the overfurther slide because it will require more power to pull the sharply curved portion 19 around the curve than is required to hold it in place. The reinforcement is therefore automatically locked to the casing when the iniiation of the tire is complete and heat by friction and by chafing are obviated in the tire, and

ies

the reinforcement is compelled' to Kdivide l with the casing the strain of the air under pressure in the inner tube and all the external strains placed on the tire while it is in use.

l contemplate forming'the reinforcement of various thicknesses and in various lengths and hence do not wish to be limited to the precise thickness or form herein described. lt will be seen that the beveled edges of the reinforcement, when the reinforcement .is placed in the tire, fare at all times above the inner edges of thetire or toes of the beads.

What claim is:

An inner reinforcement for pneumatic tires having overlapping portions along its jhmnrr periphery, the edges of which nortions are beveed an extend, in use, above witness whereof I hereunto Vsign my tle beds ofldthe tire, sad portionshbeing name this 21st day of December, 1912. a apte to s e upon eac other as t e tire is inated to cause the reinforcement to con- ALBERT LINN MURRAY 5 form to the inner Wall ofthe tire and to the Witnesses:

outer surface of the wheel rim between the A. E. HOLDEN,4 beads andloek the same within the tire. J. C. Loom 

